cannot send video attachments

Every time I try to send an attachments I get this notice. I have lowered the
security settings on internet options and turned off the anti-virus program I
would especially like to be able to send “Point and Shoot Videos� I have
recorded.
“Task 'warth publishinginc - Sending' reported error (0x800CCC80) : 'None of
the authentication methods supported by this client are supported by your
server.'�